Chapter 15.1, Problem 15.2E

Interpretation Introduction

Interpretation:

The $\text{pH}$ of the blood that contains $0.0025\text{M}$ of ${\text{HPO}}_4^{2-}$ and $0.0015\text{M}$ of ${\text{H}}_2{\text{PO}}_4^{-}$ has to be calculated.

Concept Introduction:

The buffer is a solution that resists any change in pH on addition of ${\text{H}}^{+}$ and ${\text{OH}}^{-}$.  An acidic buffer is made up of a weak acid and its salt.  A basic buffer is made up of a weak base and its salt.  The formula to calculate the $\text{pH}$ of the buffer is shown below.

$\text{pH}=-\log K_a+\log \frac{\left[{\text{A}}^{-}\right]}{\left[\text{HA}\right]}$